Indexable head switch



l Feb. 7, 1967 M, J, DOBES 3,303,298

INDEXABLE HEAD SWITCH Filed June 4. 1965 IN VENTO R. j? wa/454 J .00555y# Ryo/WM United States Patent C) 3,303,298 INDEXABLE HEAD SWITCHMichael J. Dobes, Cleveland Heights, Uhio, assignor to The National AcmeCompany, a corporation of Ohio Filed June 4, 1965, Ser. No. 461,389 17Claims. (Cl. 20G- 47) The invention relates in general to industrialswitches, such as limit switches, and more particularly to a switch witha housing having a head which may be indexed into a plurality ofpositions.

In many industrial switch applications the switch mechanism is actuatedby movement of some machine part, for example, a moving slide. Theswitch mechanism is mounted in a housing so as to be oil and dirt tight,as well as to provide mechanical and electrical protection to the actualswitch. This is necessary in most machinery applications because of theenvironment in which the industrial switch is used. Also, the switch issubject to be used in many different positions and by all types ofactuating slides or other apparatuses. Accordingly, different housingswith different mounting hole arrangements were often used in the past inorder to provide the necessary flexibility of mounting on any availablesurface for different actuating conditions. This required stockingadditional housings to house the actual switch and increasedmanufacturing and inventory costs. Alternatively, if an actuating headwere separate from a housing, it often was bolted to this housing and tochange the position thereof relative to the housing, all bolts had to beremoved, the head turned and then the bolts replaced.

Accordingly, an object of the invention is to provide a switchImechanism wherein an actuating head may be quickly indexed into any oneofpa number of plural positions to suit a number of actuatingconditions.

Another object of the invention is to provide a switch mechanism with asingle housing and single mounting means thereof onto a supportingsurface, yet with the actuating head indexable into a plurality ofpositions to permit the switch to be actuated from a number of difterentdirections.

Another object of the invention is to provide a switch mechanism with anindexing head which is urged into any of a number of positions by springmeans.

Another object of the invention is to provide a switch mechanism with aspring means which provides a dual function of attaching a head to aswitch housing and also permits the head to be indexed into pluralpositions relative to the housing..

Another object of the invention is to provide a switch mechanism with anindexable head on a housing with a means to rotatively lock the head tothe housing and a means to axially lock the head to the housing, withthe two means permitting ready removal of the head and ready indexing ofthe head relative to the housing.

The invention may be incorporated in a switch mechanism comprising, incombination, a housing; switch means mounted in said housing; anactuator on said switch means disposed for movement generally along anaxis; an indexable head; a rst wall on one of said housing and saidhead; a second mating wall on the other of said housing and said head;means to rotatively lock said head to said houshing with said first andsecond walls in engagement; aperture means in said extension coaxialtherewith; an actuator link in said head disposed in said aperture meansin said extension to actuate said switch actuator; said rotative lockmeans including a plurality of recess walls symmetrical relative to saidaxis and defining recess means on one of said houshing and said head,boss means on the other of said housing and said head entering saidrecess means to rotatively interlock therewith, and spring means urgingsaid boss means into engagement with said 3,303,298 Patented Feb. 7,1957 recess means; whereby said head may be moved axially t-o stresssaid spring means and to cause said boss means to be removed from saidrecess means to permit indexing of said head into any one of pluralpositions.

Other objects and a fuller understanding of the invention may be had byreferring to the following description and claims, taken in conjunctionwith the accompanying drawings, in which:

FIGURE 1 is a side view partially broken away of a switch mechanismincorporating the invention;

FIGURE 2 is a top view with the cover removed of the switch of FIGURE 1;

FIGURE 3 is an end view of the switch housing with the head removed;

FIGURE 4 is a side view of an alternative head for the switch mechanismof FIGURES 1 and 2;

FIGURE 5 is a plan view of a spring to hold the head; and

FIGURE 6 is a side view of the spring of FIGURE 5.

FIGURES 1 and 2 generally show a switch mechanism 11 incorporating theinvention. This switch mechanism includes generally a housing 12 and ahead 13. The head 13 may be considered an actuating head to actuate aswitch 14 contained within the housing 12. The head 13 may be referredto as a cam head. The switch 14 may be one of many varieties andincludes generally an actuator plunger 17 movable generally along anaxis 18 of the plunger 17. This axis 18 may be longitudinal of thehousing 12 and parallel to an axis 19 of this housing 12.

The housing 12 is generally hollow and rectangular and has mountingholes 21 for mounting to any available surface, such as one on amachine. A cover 22 and cover gasket 23 may be provided to completelyclose the housing 12. This cover 22 is removed in FIGURE 2. A threadedanerture 24 -may be provided at one end of the housing 12 to receive theordinary threaded conduit for mechanical protection to electricalconductors connecting to terminals 25 of the switch 14. The housing 12has an end wall 28 at one longitudinal end of the housing. This may becalled a rst wall. The head 13 has a mating wall 29 to mate with thisrst Wall 28. The first wall 28 has an interior surface 30 and anexterior surface 31. The interior surface 30 is generally rectangular.Means are provided to axially lock the head 13 on the housing 12 withthe first and second walls 28 and 29 in mating engagement. Means arealso provided to rotatively lock the head 13 to the housing 12. Thehousing wall 28 has a circular aperture 33 which is coaxial with theaxis 18. The head 13 at the wall 29 has a cylindrical extension 34 whichclosely fits within the circular aperture 33 and is coaxial therewith.These parts are also shown on the roller head 51 of FIGURE 4, which isan alternative head mountable on the housing 12. An annular groove 35 isprovided near the end of this cylindrical extension 34 and is defined atleast partially by a cylindrical wall 36 and an annular shoulder 37.This annular shoulder is an outwardly facing shoulder, facing outwardlyof the housing 12. With the head 13 mounted on the housing 12, thegroove 35 is disposed inboard of the interior surface 30 of the housingend wall 28.

A leaf spring 39 is part of the means to axially lock the head 13 on thehousing 12. This leaf spring 39 is better shown in FIGURES 5 and 6. Itis generally at and has a forked end 40 and a bight 41 of the fork whichis generally -semicylindrical and of a radius slightly larger than thecylindrical wall 36 forming part of the groove 35. The leaf spring 40 isgenerally rectangular in outline to be received against the rectangularinner wall 30. Spring 4t) has an aperture 42 which, in use, may bepositioned close to the cover 22. This permits the leaf spring 39 to begrasped, as by a tool, `at this aperture 42, so that the spring may beremoved from the housing 12. The forked end 40 of the spring 39 is bentat a small angle, for example, degrees; and as shown in FIGURE 1, thispermits the forked end to engage the interior surface 30 of the wall 28at the same time that the bight of the fork engages the annular shoulder37. This slightly stresses the spring 39, yet permits ready insertion ofthe spring into the housing 12 with the cover 22 removed. Also, thisslight stressing of the spring axially locks the head 13 onto thehousing 12. This stressing of the spring 39 permits the head 13 to beresiliently urged into engagement with the housing 12. With the cover 22removed, the leaf spring 39 is readily removed and this permits the head13 to be readily removed in an axial direction from the housing 12.

The means to rotatively lock the head 13 on the housing 12 includes bossmeans engaging with recess means generally at the mating walls 28 and29. This rotative locking means is shown as including a recess 45disposed in the first wall 28. This recess 45 is defined by recess walls46 which define a polygonal recess, in this case shown as a squarerecsss. These walls 46 are four in number with the recess being squareand they may also be called shoulder walls. This square recess 45 iscoaxial with the axis 18 and surrounds the circular aperture 33.

FIGURE 4 shows an alternative roller head 51 which may be substitutedfor the cam head 13. In order to inountthis roller head 51 on thehousing 12, it also has the Icylindrical extension 34 and annular groove35. This FIGURE 4 better shows the boss 52 on these heads 13 and 51which will enter and mate with the recess 45. This boss 52 is apolygonal boss and in this case is shown as a square boss to mate withthe square recess 45. The boss 52 has boss walls 53, shown to be fou-rin number, defining the periphery of this boss 52. This boss 52 isconcentric with the -cylindrical extension 34 so as to be disposed inthe recess 45 at the saine time that the cylindrical extension 34 isdisposed in the circular aperture 33.

The head 13 has aperture means 55 disposed along the axis 18 to slidablyreceive a link 56. This link is actuated in the head by a cam 57 to bemoved longitudinally to act on the switch actuator plunger 17 to actuatethe switch 14. The cam 57 may be actuated in turn by a lever 58 carryinga roller 59. The roller 59 is adapted to be actuated by some machineelement, such as a slide or other movable member, not shown.

The roller head 51 contains a longitudinal slidable actuator link 61carrying a roller 62 at the end opposite a cylindrical extension 34.This roller 62 may be actuated by some machine element, such as a slide,so that the actuator link 61 may move longitudinally and actuate theswitch plunger 17.

OPERATION The switch 11 may be mounted to a ma-chine in any suitablemanner, such as by bolts through the mounting holes 21. It may bemounted on any suitable mounting surface and these will vary widelydepending upon the machine with which the industrial switch 11 is used.The actuating mechanism to actually strike the roller 59 for 62 of thecam head 13 or `roller head 51 may also vary widely with the machine.Accordingly, it has been found that the switch mechanism 11 has definiteadvantages of being able to index the head 13 or 51, or any other ofseveral actuating heads, into a plurality of positions. In the case ofthe switch shown, four positions are possible because of the squarerecess 45. The head 13 or 51 may be grasped and pulled axially outwardlyto stress the spring 39. This will permit the boss 52 to be removed fromthe recess 45 and then this head may be turned into any one of fourpositions 90 degrees apart. This will dispose the lever 58 on differentsides of the housing 12 and so permit the switch to be actuated fromfour different directions. This is a definite advantage in flexibilityor actuation of the switch, because the surface on which the switch ismounted may not be parallel to the direction in which the actuatingslide is moved. Also, the head 51 may just as easily be indexed and thispermits the roller 62 to `be actuated by a slide mechanism moving in adirection to easily actuate the roller 62, rather than moving in adirection parallel to the bearing axis 4of the roller 62, which wouldbreak off the roller rather than actuating it.

The leaf spring 39 acts both in the means to rotatively lock the headand the means to axially lock the head to the housing 12. The spring 39is slightly stressed in the normal position of assembly. This urges thehead 13 axially toward the housing 12 to maintain a dirt-tight andgenerally oil-tight enclosure for the switch 14. The spring 39 isstressed still further when the head is pulled outwardly to remove theboss 52 from the `recess 45. This permits the head 13 to be indexed into-a plurality of positions. Thus, the spring 39 serves a dual functionpet'- mitting the head 13 to be readily removed and also to be readilyindexed. The boss walls 53 vare disposed in close proximity to therecess walls 46 under the urging of the spring 39. This rotatively locksthe head 13 in any one of plural positions. It will therefore, be seenthat just one of these boss walls 53, cooperating with the correspondingrecess wall 46, may be considered to be that which rotatively locks thehead 13 in any one of plural positions depen-dent upon the number ofrecess walls 46. The recess walls 46 are symmetrical relative to theaxis 18 because the recess 45 is coaxial with the circular aperture 33.This symmetry permits the boss walls to mate with the recess walls forany one of the plural positions.

The .forked end on the leaf spring 39 is a form of aperture in this leafspring 39 permitting this spring to act between the annular shoulder 37and the housing 12 at the end wall 28.

The present disclosure includes that contained in the appended claims,as well as that of the foregoing description.

Although this invention has 'been described in its preferred form with acertain degree of particularity, it is understood that the presentdisclosure of the preferred form has been made only by way of exampleand that numerous changes in the details yof construction and thecombination and arrangement of parts may be resorted to withoutdeparting from the spirit and the scope of the invention as hereinafterclaimed.

What is claimed is:

1. A switch mechanism comprising, in combination:

a housing;

switch means mounted in said housing;

an actuator on said switch means disposed for movement generally alongan axis;

an indexable head;

a first wall on one of said housing and said head;

a second mating wall on the other of said housing and said head;

means to rotatively lock said head to said housing with said first andsecond walls `in engagement;

an extension on one of said walls extending through a coaxial apertureon the other of said walls,

aperture means in said extension coaxial therewith;

an actuator link in said head disposed in said aperture means in saidextension to actuate said switch actuator; said rotative lock meansincluding a plurality of recess walls symmetrical relative to said axisand defining recess means on one of said housing and said hea-d,

boss means on the other of said housing and said head entering saidrecess means to rotatively interlock therewith,

and spring means urging said boss means into engagement with said recessmeans; whereby said head may be moved axially to stress said springmeans and to cause said boss means to be removed from said recess meansto permit indexing of said head into any one of plural positions.

2. A switch mechanism comprising, in combination,

a housing,

switch means mounted in said housing,

an actuator on said switch means disposed for movement generally alongan axis,

an indexable head,

a first wall on one of said housing and said head,

a second mating wall on the other of said housing and said head,

means to :axially lock said head on said housing with said first andsecond walls in engagement,

means to rotatively lock said head to said housing,

said axial ylock means including an extension on one of said wallsextending through a coaxial aperture on the other of said `walls andincluding an outwardly facing shoulder on said etxension engaged byspring means,

aperture means in said extension coaxial therewith,

an actuator link yin said head disposed in said aperture means in saidextension to actuate said switch actuator,

said rotative lock means including boss means on one of said 4wallsurged by said spring means into at leas-t one of a plurality of recesswalls symmetrical relative to said axis and defining recess means on theother of said walls, whereby said head may be moved axially to stresssaid spring means and to cause said boss means to be removed from saidrecess means to permit indexing of said head into any one of pluralpositions equal to the number ot recess walls.

3. A switch mechanism comprising, in combination,

a housing;

switch means mounted in said housing;

an actuator on said switch means disposed for movement generally alongan axis;

an indexable head;

a first wall on one of said housing and said head;

a second mating wall on the other `of said housing and said head;

means to axially lock said head on said housing with said first andsecond walls in engagement;

means to rotatively lock said head to said housing;

said axial lock means including a circular aperture through said firstwall,

an extension on said second wall extending through said first wallaperture,

an outwardly facing shoulder near the end of said extension,

and spring means engaging said shoulder and sait` first wall;

aperture means in said extension coaxial therewith;

an actuator link in said head disposed in said aperture means in saidextension to actuate said switch actuator;

said rotative lock means including a plurality `of' recess wallssymmetrical relative to said `axis and defining `recess means on one ofsaid housingv and said head,

and boss means on the other of said housing and said head entering saidrecess means to rotatively interlock therewith;

and said spring means urging said boss means into engagement with saidrecess means;

whereby said head may be moved axially to stress said spring means andto cause said boss means to be removed from said recess means to permitindexing of said head into any one of plural positions equal to thenumber of recess walls.

4. A switch mechanism comprising, in combination, a housing, switchmeans mounted in said housing, an actuator on said switch means disposedfor movement generally along an axis, an indexable head, a first Wall onone of said housing and said head, a second mating wall on the other ofsaid housing and said head,

means to axially lock said head o'ri said housing with said first andsecond Walls in engagement,

means to rotatively lock said head to said housing,

said axial lock means including an extension on one of said wallsextending through a coaxial aperture on the other of said walls andincluding an outwardly facing shoulder on said extension engaged byspring means,

aperture means in said extension coaxial therewith,

an actuator link in said head disposed in said aperture means in `saidextension to actuate said switch actuator,

said rotative lock means including a plurality of recess wallssymmetrical relative to said axis and dening recess means on one of saidhousing and said head and boss means on the other of said housing andsaid head urged into said recess means by said spring means torot-atively interlock therewith,

whereby said head may be moved axially to stress said spring means andto cause said boss means to be removed from said recess means to permitindexing of said head into any one of plural positions equal to thenumber of recess walls.

5. A switch mechanism comprising, in combination,

a housing,

switch means mounted in said housing,

an actuator on said switch means disposed for movement generally alongan axis,

an indexable head,

a first wall on one of said housing and said head,

a second wall on the other of said housing and said head,

said first wall having an interior and an exterior surface,

a circular aperture through said first wall coaxial wit-h said switchactuator axis,

an extension on said second wall closely fitting concentrically withinsaid circular aperture,

aperture means in said extension coaxial therewith,

an actuator link in said head disposed in said aperture means in saidextension to actuate said switch actuator,

a plurality of recess walls symmetrical relative to said axis anddefining recess means on one of said housing and said head,

boss means on the other of said housing and said head entering saidrecess means to rotatively interlock therewith,

an outwardly facing shoulder on said extension and disposed inboard ofthe interior surface of said first wall,

spring means urging said boss means into engagement with said recessmeans,

and means including said spring means acting between said interiorsurface of said first wall and said shoulder to retain said head on saidhousing,

whereby said head may be moved axially to stress said spring means andto cause said boss means to be removed from said -recess means to permitindexing of said head into any one of plural positions equal to thenumber of recess walls.

6. A switch mechanism comprising, in combination,

a housing,

switch means mounted in said housing,

an actuator on said switch means disposed for movement along an axis,

an indexable head,

a rst wall on one of said housing and said head,

a second wall on the other of said housing and said head,

said first wall having an interior and an exterior surface,

a circular aperture through said first wall coaxial wit-h said switchactuator axis,

an extension on said second wall closely fitting concentrically withinsaid circular aperture,

aperture means in said extension coaxial therewith,

an actuator link in said head disposed in said aperture means in saidextension to actuate said switch actuator,

a plurality of recess walls symmetrical relative to said axis anddefining recess means on one of said housing and said head,

boss means on the other of said housing and said head entering saidrecess means to rotatively interlock therewith,

an outwardly facing shoulder on said extension and disposed inboard -ofthe interior surface of said first wall,

and means including spring means engaging said shoulder to lock saidhead on said housing in an axial direction and resiliently urging saidhead in one axial direction relative to said housing,

whereby said head may be moved in the opposite axial direction to stresssaid spring and to cause said boss means to be removed from said recessmeans to permit indexing of said head into any one of plural positionsequal to the number of recess walls.

7. A switch mechanism comprising, in combination, a

housing,

switch means mounted in said housing,

an actuator on said switch means disposed for movement along an axis,

an indexable head,

a first wali on one of said housing and said head,

a second wall on the other of said housing and said head,

said first wall having an interior and an exterior surface,

a circular aperture through said first wall coaxial with said switchactuator axis,

an extension on said second wall closely fitting concentrically withinsaid circular aperture,

a plurality of recess walls symmetrical relative to said axis anddefining recess means on the exterior surface of one of said walls,

boss means on the other of said walls entering said recess means torotatively interlock therewith,

wall means including an outwardly facing shoulder on said extension anddisposed inboard of the interior surface of said first wall,

a leaf spring having an aperture received over said extension andstressed between said interior surface of said first wall and saidshoulder to resiliently urge said extension inwardly of said wallaperture, whereby said head may be pulled axially outwardly to stresssaid spring and to cause said boss means to be removed from said recessmeans to permit indexing of said head into any one of plural positionsequal to the number of recess walls,

aperture means in said extension coaxial therewith,

and an actuator llink in said head disposed for longitudinal slidingmovement through said aperture means in said extension to actuate saidswitch actuator.

8. A switch mechanism comprising, in combination,

a housing,

switch means mounted in said housing,

an actuator on said switch means disposed for movement along an axis,

a removable and indexa'ble head,

a first wall on one of said housing and said head,

a second wall on the other of said housing and said head,

said first wail having an interior and an exterior surface,

a circular aperture through said first wall coaxial with said switchactuator axis,

an extension on said second wall closely fitting concentrically withinsaid circular aperture,

a plurality of recess walls symmetrical relative to said axis `anddefining recess means on the exterior surface of one of said walls,

boss means on the other of said walls entering said recess means torotatively interlock therewith,

wall means including an outwardly facing shoulder on said extension anddisposed inlboard of the interior surface of said first wall,

a leaf spring having a forked end having a dimension to be receivedagainst said shoulder,

said leaf spring having one part engaging said interior surface of saidfirst wall and another part engaging said shoulder to resiliently urgesaid extension inwardly of said aperture, whereby said head may bepulled axially outwardly to stress said spring and to cause said bossmeans to be removed from said recess means to permit indexing of saidhead into any one of p-lural positions and whereby said spring may beremoved in a direction perpendicular to said axis to permit removal ofsaid head from said housing along said axis,

aperture means in said extension coaxial therewith,

and an actuator link in said head disposed for longitudinal slidingmovement through said aperture means in said extension to actuate saidswitch actuator.

9. A switch mechanism comprising, in combination,

a housing,

switch means mounted in said housing,

an actuator on said switch means disposed for movement along an axis,

an indexable head,

a first wall on one of said housing and said head,

a second wall on the other of said housing and said head,

said first wall having an interior and an exterior surface,

a circular aperture through said first wall coaxial with said switchactuator axis,

an extension on said second wall closely fitting concentrically withinsaid circular aperture,

a shoulder wall defining a polygonal recess on the exterior surface ofone of said walls concentric with said aperture and extension,

boss wall means on the other of said walls entering said polygonalrecess to rotatively interlock therewith,

Wall means including an outwarlly facing annular shoulder on saidextension and disposed inboard of the interior surface of said firstwall,

a generally fiat but slightly curved leaf spring having an aperturereceived over said extension,

means to cause said leaf spring to act between and be slightly stressedbetween said interior surface of said first wall and said annularshoulder to resiliently urge said extension inwardly of said wallaperture, whererby said head may be pulled axially outwardly to furtherstress said spring and to cause said boss wall means to Ibe removed fromsaid recess to permit ndexing of said head into any one of pluralpositions equal to the number of sides of said polygonal recess,

aperture means in said extension coaxial therewith,

and an actuator link in said head disposed for longitudinal slidingmovement through said aperture means in said extension to actuate saidswitch actuator.

10. A switch mechanism comprising, in combination,

a housing,

switch means mounted in said housing,

an actuator on said switch means disposed for movement along an axis,

a removable and indexable head,

a first wall on one of said housing and said head,

a second wall on the other of said housing and said head,

said first wall having an interior and an exterior surface,

a circular aperture through said first wall coaxial with said switchactuator axis,

an extension on said second wal-l closely fitting concentrically withinsaid circular aperture,

a shoulder wall defining a polygonal recess on the exterior surface ofone of said walls concentric with said aperture and extension,

boss wall means on the other of said walls entering said polygonalrecess to mate closely therewith,

wall means including lan outwardly facing annular shoulder on saidextension and disposed inboard of the interior surface of said firstwall,

a generally fiat leaf spring having a forked end with the bight of thefork having a dimension to be received against said annular shoulder,

said forked end being bent at a small angle so that the two ends of thefork engage said interior surface of said first wall and the bight ofthe fork engages said annular shoulder to resiliently urge saidextension inwardly of said aperture, whereby said head may be pulledaxially outward-ly to stress said spring and to cause said boss Wallmeans to be removed from said recess to permit indexing of said headinto any one of plural positions equal to the number of sides of saidpolygonal recess and whereby said spring may be removed in a directionperpendicular to said axis to permit removal of said head from saidhousing along said axis,

aperture means in said extension coaxial therewith,

and an actuator llink in said head disposed for longitudinal slidingmovement through said aperture means in said extension to lactuate saidswitch actuator.

lll. A switch mechanism comprising, in combination,

a housing,

switch means mounted in said housing,

an actuator on said switch means disposed for movement along an axis,

a removable and indexable head,

a first wall on one of said housing and said head,

a second wall on the other of said housing and said head,

said first wall having an interior and an exterior surface,

a circular aperture through said first wall coaxial with said actuatoraxis,

a cylindrical extension on said second wall closely fittingconcentrically within said circular aperture,l

a shoulder wall defining a polygonal recess on the exterior surface ofone of said walls concentric with said aperture and extension,

boss wall means defining a polygonal boss on the other of said wallsconcentric with said aperture and said cylindrical extension andentering said polygonal recess to mate closely therewith,

wall means including an outwardly facing annular shoulder on saidcylindrical extension and disposed inboard of the interior surface ofsaid first wall,

a generally flat leaf spring having a forked end with the bight of thefork having a dimension to be re ceived against said annular shoulder,

said forked end being bent at a small angle so that the two ends of thefork engage said interior surface of said first wall and the bight ofthe fork engages said annular shoulder to resiliently urge saidcylindrical extension inwardly of said aperture, whereby said head maybe pulled axially outwardly to stress said spring and to cause said bossto be removed from said recess to permit indexing of said head into anyone of plural positions equal to the number of sides of said'polygonalrecess,

aperture means in said cylindrical extension coaxial therewith,

and an actuator link in said head disposed for longitudinal slidingmovement through said aperture means in said cylindrical extension toactuate said switch actuator.

12. A switch mechanism comprising, in combination, a

housing,

switch means mounted in said housing,

an actuator plunger on said switch means disposed along an axis,

an end wall at one longitudinal end of said housing and having aninterior and an exterior surface,

a circular aperture through said end wall coaxial with said plungeraxis,

a removable and indexable head on said end wall of said housing,

a cylindrical extension on said head closely fitting within saidcircular aperture,

boss wall means defining a polygonal boss,

a shoulder wall defining a polygonal recess to mate closely with saidboss,

said boss being on one -of said housing and said head,

said recess being on the other of said housing and said head,

wall means defining an outwardly facing annular shoulder on saidcylindrical extension and disposed inboard of the inner surface of saidhousing end wall to be within said housing,

spring means acting between said end wall interior surface and saidannular shoulder to resiliently urge said head inwardly of said housing,whereby said head may be pulled axially outwardly to stress said springmeans and to cause said boss to be removed from said recess to permitindexing of said head into any one of plural positions equal to thenumber of sides of said polygonal recess,

aperture means in said cylindrical extension co-axial therewith,

and an actuator link in said head disposed for longitudinal slidingmovement through said aperture means-in said cylindrical extension toactuate said actuator plunger.

13. A switch mechanism comprising, in combination,

a housing,

switch means mounted in said housing,

an actuator plunger on said switch means disposed along an axis,

a removable and indexable head,

a first wall on one of said housing and said head,

a second Wall on the other of said housing and said head,

said first wall having an interior and an exterior surface,

a circular aperture through said first wall coaxial with said plungeraxis,

a cylindrical extension on said second wall closely fitting within saidcircular aperture a shoulder wall defining a polygonal recess on theexterior surface of said first wall concentric with said aperture,

boss wall means defining a polygonal boss on said second wall concentricwith said cylindrical extension and entering said polygonal recess tomate closely therewith,

wall means including an annular shoulder defining an annular groove onsaid cylindrical extension and disposed inboard of the interior surfaceof said first wall,

a generally fiat leaf spring having a forked end with the bight of thefork having a dimension slightly larger than the diameter of saidannular groove to be received in said annular groove,

said forked end being bent at a small angle so that the two ends of thefork engage said interior surface of said first wall and the bight ofthe fork engages said annular shoulder of said annular groove toresiliently urge said cylindrical extension inwardly of said aperture,whereby said head may be pulled axially outwardly to stress said springand to cause said boss to be removed from said recess to permit indexingof said head into any one of plural positions equal to the number ofsides of said polygonal recess, aperture means in said cylindricalextension coaxial therewith,

and an actuator link in said head disposed for longitudinal slidingmovement through said aperture means in said cylindrical extension toactuate said actuator plunger.

14. A swtich mechanism comprising, in combination,

housing,

switch means mounted in said housing,

an actuator plunger on said switch means disposed along an axis,

an end wall at one longitudinal end of said housing and having aninterior and an exterior surface,

a circular aperture through said end wall coaxial with said plungeraxis,

a removable and indexable head on said end wall of said housing,

a cylindrical extension on said head closely fitting within saidcircular aperture,

a shoulder wall defining a polygonal recess concentric with saidaperture on one of said wall exterior and said head,

boss wall means defining a polygonal boss on the other of said wallexterior surface and said head and concentric with said aperture andentering said polygonal recess to mate closely therewith,

wall means including an annular shoulder defining an annular groove onsaid cylindrical extension and disposed inboard of the interior surfaceof said housing end wall to be within said housing,

a generally flat leaf spring having a forked end with the bight of thefork having a dimension slightly larger than the diameter of saidannular groove to be received in said annular groove,

said forked end being bent at a small angle so that the two ends of thefork engage said interior surface of said housing end wall and the bightof the fork engages said annular shoulder of said annular groove toresiliently urge said head inwardly of said housing, whereby said headmay be pulled longitudinally outwardly to stress said spring and tocause said boss to be removed from said recess to permit indexing ofsaid head into any one of a number of plural positions equal to thenumber of sides of said polygonal recess,

aperture means in said cylindracl extension coaxial therewith,

and an actuator link in said head disposed for longitudinal slidingmovement through said aperture means in said cylindrical extension toactuate said actuator plunger.

15. A switch mechanism comprising, in combination,

an elongated housing with a longitudinal axis,

an end -wall at one longitudinal end of said housing,

a circular aperture through said end wall parallel to the longitudinalaxis of said housing,

a shoulder wall defining a polygonal recess on the exterior surface ofsaid end wall concentric with said aperture,

a removable and indexable head on said end wall of said housing,

a cylindrical extension on said head closely fitting within saidcircular aperture,

boss wall means defining a polygonal boss on said head concentric withsaid cylindrical extension and entering said polygonal recess on saidhousing and wall to mate closely therewith,

wall means defining an annular groove on said cylindrical extension anddisposed inboard of the inner surface of said housing end wall to bewithin said housing,

a generally flat leaf spring having a forked end with the bight of thefork having la dimension slightly larger than the diameter of saidannular groove to `be received in said annular groove,

said forked end being bent at a small angle so that the two ends of thefork engage said inner surf-ace of said housing end wall and the bightof the fork engages the wall means defining said annular groove toresiliently urge said head inwardly of said housing, whereby said headmay be pulled longitudinally outwardly to stress said spring and tocause said boss to be removed from said recess to permit indexing ofsaid head into any one of a number of plural positions equal to thenumber of sides of said polygonal recess,

switch means mounted in said Vhousing,

an actuator plunger on said switch means disposed along the axis of saidcircular aperture,

aperture means in said cylindrical extension Coaxial therewith Iariddisposed parallel to said longitudinal axis,

and an actuator link in said head disposed for longitudinal slidingmovement through said aperture means in said cylindrical extension toactuate said actuator plunger.

16. An industrial switch mechanism comprising, in combination, anelongated lgenerally rectangular hollow Ihousing with a longitudinalaxis,

yan end wall at one longitudinal end of said housing, the

inner surface of said end wall being rectangular,

a circular aperture through said end wall parallel to the longitudinalaxis of said housing,

a shoulder 'wall defining a square recess on the exterior surface ofsaid end wall concentric with said aperture,

a removable and indexable head on said end wall of said housing,

a cylindrical extension on said head closely fitting within saidcircular aperture,

boss wall means defining a square boss on said head concentric `withsaid cylindrical extension and entering said square recess on saidhousing 'and wall to mate closely therewith,

wall means defining an annular groove on the exterior cylindricalsurface near the outer end of said cylindrical extension and disposedinboard of the inner surface of said housing end wall to be within saidhousing,

a generally fiat leaf spring having a forked end with the bight of thefork `generally semicircular and of a radius slightly larger than theradius of said annular groove to be received in said annular groove,

said leaf spring being generally rectangular in outline to be receivedin close proximity to the rectangular inner surface of said housing endwall,

said forked end being bent at a small angle so that the two ends of thefork engage said inner surface of said housing end wall and the bight ofthe fork engages the wall Imeans defining said yannular groove toresilient-ly urge said head inwardly of said housing, whereby said headmay be pulled longitudinally outwardly to stress said spring and tocause said boss to be removed from said recess to permit indexing ofsaid head into any one of four positions 90 degrees apart,

switch means mounted in said housing,

an actuator plunger on said switch means disposed along the axis of saidcircular aperture,

Iaperture means in said cylindrical extension coaxial therewith anddisposed parallel to said longitudinal axis,

an actuator link in said head disposed for longitudinal sliding movementalong the axis of said cylindrical extension and through said aperturemeans in said cylindrical extension to actuate said actuator plunger,

and an actuator roller on an exterior end of said actuator link forexternal engagement.

17. An industrial switch mechanism comprising, in combination, anelongated generally rectangular hollow housing with a longitudinal axis,

an end wall at one longitudinal end of said housing, the

inner surface of said end wall being rectangular,

a circular aperture through said end wall parallel to the longitudinalaxis of said housing,

a square recess on the exte-rior surface of said end wall concentricwith said aperture,

a removable and indexable head on said end wall of said housing,

a cylindrical extension on said head entering and closely fitting withinsaid circular aperture,

a square boss on said head concentric with said cylindrical extensionand entering said square recess on said housing and wall to lmateclosely therewith,

wall means dening an annular groove on the exterior cylindrical surfacenear the outer end of said cylindrical extension and disposed inboard ofthe interior surface of said housing end wall to be within said housing,

a generally flat lea-f spring having a forked end and an apertured end,said forked end having the bight of the fork generally semicircular andof -a radius slightly larger than the radius of said annular groove tobe received in said annular groove,

said leaf spring being generally rectangular in outline to be receivedin close proximity to the rectangular inner surface of said housing endwall,

said apertured end of said leaf spring permitting grasping of the lleafspring to permit its removal from said annular groove and from saidhousing,

said forked end being bent at approximately a l0 degree angle so thatthe tw-o ends of the fork engage said inner surface of said housing endwall and the bight of the fork engages the wall means defining saidannular groove to resiliently urge said head inwardly of said housing,whereby said head may -be pulled longitudinally -outwardly to stresssaid spring and to cause said bossto be removed from said recess topermit indexing of saidhead into any one of four positions degreesapart,

switch means mounted in said housing,

an actuator plunger on said switch means disposed along the axis of saidcircula-r aperture,

cam means in said head,

aperture means in said cylindrical extension coaxial therewith and`disposed parallel to said longitudinal ax1s,

link means in said aperture means to act between said cam means and saidactuator plunger to actuate same 'upon rotation of said cam means,

and an actuating lever pivotally mounted in said head to rotate saidcam.

No references cited.

BERNARD A. GILHEANY, Primary Examiner.

1. A SWITCH MECHANISM COMPRISING, IN COMBINATION: A HOUSING; SWITCHMEANS MOUNTED IN SAID HOUSING; AN ACTUATOR ON SAID SWITCH MEANS DISPOSEDFOR MOVEMENT GENERALLY ALONG AN AXIS; AN INDEXABLE HEAD; A FIRST WALL ONONE OF SAID HOUSING AND SAID HEAD; A SECOND MATING WALL ON THE OTHER OFSAID HOUSING AND SAID HEAD; MEANS TO ROTATIVELY LOCK SAID HEAD TO SAIDHOUSING WITH SAID FIRST AND SECOND WALLS IN ENGAGEMENT; AN EXTENSION ONONE OF SAID WALLS EXTENDING THROUGH A COAXIAL APERTURE ON THE OTHER OFSAID WALLS, APERTURE MEANS IN SAID EXTENSION COAXIAL THEREWITH; ANACTUATOR LINK IN SAID HEAD DISPOSED IN SAID APERTURE MEANS IN SAIDEXTENSION TO ACTUATE SAID SWITCH ACTUATOR; SAID ROTATIVE LOCK MEANSINCLUDING A PLURALITY OF RECESS WALLS SYMMETRICAL RELATIVE TO SAID AXISAND DEFINING RECESS MEANS ON ONE OF SAID HOUSING AND SAID HEAD, BOSSMEANS ON THE OTHER OF SAID HOUSING AND SAID HEAD ENTERING SAID RECESSMEANS TO ROTATIVELY INTERLOCK THEREWITH, AND SPRING MEANS URGING SAIDBOSS MEANS INTO ENGAGEMENT WITH SAID RECESS MEANS; WHEREBY SAID HEAD MAYBE MOVED AXIALLY TO STRESS SAID SPRING MEANS AND TO CAUSE SAID BOSSMEANS TO BE REMOVED FROM SAID RECESS MEANS TO PERMIT INDEXING OF SAIDHEAD INTO ANY ONE OF PLURAL POSITIONS.